#!/bin/sh

# Copyright (C) 2017-2024 Internet Systems Consortium, Inc. ("ISC")
#
# This Source Code Form is subject to the terms of the Mozilla Public
# License, v. 2.0. If a copy of the MPL was not distributed with this
# file, You can obtain one at http://mozilla.org/MPL/2.0/.

# Exit with error if commands exit with non-zero and if undefined variables are
# used.
set -eu

# shellcheck disable=SC2034
# SC2034: ... appears unused. Verify use (or export if used externally).
prefix="@prefix@"

# Include utilities based on location of this script. Check for sources first,
# so that the unexpected situations with weird paths fall on the default
# case of installed.
script_path=$(cd "$(dirname "${0}")" && pwd)
if test "${script_path}" = "@abs_top_builddir@/src/share/database/scripts/pgsql"; then
    # shellcheck source=./src/bin/admin/admin-utils.sh.in
    . "@abs_top_builddir@/src/bin/admin/admin-utils.sh"
else
    # shellcheck source=./src/bin/admin/admin-utils.sh.in
    . "@datarootdir@/@PACKAGE_NAME@/scripts/admin-utils.sh"
fi

VERSION=$(pgsql_version "$@")

if [ "$VERSION" != "3.1" ]; then
    printf 'This script upgrades 3.1 to 3.2. '
    printf 'Reported version is %s. Skipping upgrade.\n' "${VERSION}"
    exit 0
fi

psql "$@" >/dev/null <<EOF
START TRANSACTION;

-- This line starts the schema upgrade to version 3.2.

-- Remove constraints which perform too restrictive checks on the inserted
-- host reservations. We want to be able to insert host reservations which
-- include no specific IPv4 address or those that have repeating subnet
-- identifiers, e.g. IPv4 reservations would typically include 0 (or null)
-- IPv6 subnet identifiers.
ALTER TABLE hosts DROP CONSTRAINT key_dhcp4_ipv4_address_subnet_id;
ALTER TABLE hosts DROP CONSTRAINT key_dhcp4_identifier_subnet_id;
ALTER TABLE hosts DROP CONSTRAINT key_dhcp6_identifier_subnet_id;

-- Create partial indexes instead of the constraints that we have removed.

-- IPv4 address/IPv4 subnet identifier pair is unique if subnet identifier is
-- not null and not 0.
CREATE UNIQUE INDEX hosts_dhcp4_ipv4_address_subnet_id ON hosts
       (ipv4_address ASC, dhcp4_subnet_id ASC)
    WHERE ipv4_address IS NOT NULL AND ipv4_address <> 0;

-- Client identifier is unique within an IPv4 subnet when subnet identifier is
-- not null and not 0.
CREATE UNIQUE INDEX hosts_dhcp4_identifier_subnet_id ON hosts
        (dhcp_identifier ASC, dhcp_identifier_type ASC, dhcp4_subnet_id ASC)
    WHERE (dhcp4_subnet_id IS NOT NULL AND dhcp4_subnet_id <> 0);

-- Client identifier is unique within an IPv6 subnet when subnet identifier is
-- not null and not 0.
CREATE UNIQUE INDEX hosts_dhcp6_identifier_subnet_id ON hosts
        (dhcp_identifier ASC, dhcp_identifier_type ASC, dhcp6_subnet_id ASC)
    WHERE (dhcp6_subnet_id IS NOT NULL AND dhcp6_subnet_id <> 0);

-- Update the schema version number.
UPDATE schema_version
    SET version = '3', minor = '2';

-- This line concludes the schema upgrade to version 3.2.

-- Commit the script transaction.
COMMIT;

EOF
